**6. Conclusions**

In this article, frequency regulation was provided by a wind farm using a fuzzy logic-based controller. The proposed droop controller maintained stable and proper droop rates while providing adequate frequency support. The droop controller is designed based on the available power of the WES and the rate of change in the grid's frequency at the PCC. The fuzzy logic improved the performance of the dynamic controller. The difference between the nadir point and the nominal value of the frequency is decreased. The constant curve does not work well for WES application because of the variable nature

in wind velocity. Even though the fast rate (static) provides a very sharp response against frequency drop, it could lead to instability to the machine-side controller that is responsible for rotational speed. Also, it may increase the stresses and mechanical loading for the structure of the WES. Thus, having a dynamic droop rate that changes based on the availability of wind power and the rate of change of the frequency ensures a stable and smooth response of WES during frequency deviation.

**Author Contributions:** The authorship is equally shared, where M.G.S. served as the doctoral adviser for A.B. in his Ph.D. program at Colorado School of Mines.

**Funding:** This research received no external funding.

**Conflicts of Interest:** The authors declare no conflict of interest.
